Terminal block for electrical measuring instruments.



W. M. BRADSHAW & W. G. MYLIUS.

TERMINAL BLOCK FOR ELECTRICAL MEASURING INSTRUMENTS.

APPLICATION FILED FEB. 3. 19l6.

Patented Dec. 31, 1918;

INVENTORS William M. Bradsham Waher G. My Hus.

ATTORNEY UNITED STATES PATENT ()FFICE.

WILLIAM M. BRADSHAW AND WALTER G. MYLIUS, OF WILKINSBURG, PENNSYLVANIA,

ASSIGNORS TO WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A COR- PORATION OF PENNSYLVANIA.

TERMINAL BLOCK FOR ELECTRICAL MEASURING INSTRUMENTS.

Specification of Letters Patent.

' Patented Dec. 31, 1918.

Application filed February 3, 1916. Serial No. 75,953.

To all whom it may concern:

Be it known that We, WILLIAM M. BRAD- SHAW, a citizen of the United States, and a resident of Wilkinsburg, in the county of Allegheny and State of Pennsylvania, and WALTER G. MrLrUs, a citizen of the United States, and a resident of Wilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Imrovement in Terminal Blocks for Electrical easuring Instruments, of which the following is a specification.

Our inventlon relates to electrical measurg instruments and particularly to terminal blocks therefor.

The object of our invention is to provide a terminal block of such form, dimensions and structural characteristics as shall adapt it to the service to be performed.

Heretofore, terminal blocks were constructed either by forming an insulating member around connectors or. by inserting connectors in an insulating member. Considerable difficulty was encountered, when devices were used that were constructed in accordance with the former method, because, in many cases, the unequal expansion of the conducting and the insulating material fractured the insulating member and'thus impaired its insulating roperties. When the latter method was use it was frequently diflicult to insert the connector in the insulating member because of irregularities therein.

In order toconstruct a terminal block that will not be subject to fracture because of the unequal expansionof the insulating member and the contact terminals, and that will preclude the trouble encountered by irregularities in the insulating members, we provide an insulating member having a recess therein from which relatively large openings extend upwardly and downwardly. We dispose, in the recess and at the upper part of the insulating member adjacent the openings, a plurality of termmal members having openings therein that register with the openings in the insulating member, and we insert a bolt or other connecting member through the terminal members and the upwardly extending openings to secure the terminal members adjustably in position. The terminal members are provided. with binding screws to facilitate connecting conductors thereto.

In the accompanying drawings, Figure 1 1s a front View, partially in elevation and partially in section, of a terminal block embodylng our invention, Fig. 2 is a sectional view taken along the line IIII of Fig. 1 and Figs. 3, 4 and 5 are fragmentary sectlonal views taken along the lines IIIIII, IVIV and V-V, respectively, of Fig. 1.

A non-absorbent insulating member 1, thatis constructed of porcelain or other nonhydroscopic material, is provided with a main body portion 2 and an inwardly ex tending portion 3. The portion 3 of the insulating member 1 extends through an openmg 4 into the casing 5 of an electrical measuring instrument, and the portion 2 is adapted to fit securely in a casing 6 that is se-' cured to one side of the casing 5. The portion 2 of the insulating member 1 is provided' with a recess 7 and a plurality of relatively large openings 8 and 9 extend inof electrically connecting the terminal members 10 and 12, and for the purpose of securing the same in position. The bolts 14 are smaller in cross section than the openings 3' to permit unobstructed insertion thereof.

Pads 15 of resilient material, such, for example, as felt or rubber, are disposed between the terminal members 12 and the portion 3 of the insulating member 1 for the purpose of permitting unequal expansion of the members 10, 12 and 1. sirable to dispose resilient pads 16 between the casing 5 and the insulating member 1, substantially as shown in Fig. 2 of the draw lngs.

An auxiliary terminal member 17 is disposed in the recess 7, and acorresponding terminal member 18 is disposed adjacent the It is also de-.

inner end of an opening 21 in the portion 3 of the insulating member 1. The terminal members 17 and 18 are provided with openings 19 that register with the opening 21 for the purpose of receiving a connecting bolt .20. A conducting strap 22 is operatively connected to one of the terminal members 10 and extends substantially in front of the terminal member 17. The terminal member 17 is provided with a screw hole for the reception of a screw 23 that is adapted to operatively connect the strap 22 thereto. The terminal members 12 and 18 are provided with binding screws 24 for the purpose of securing conductors thereto, and the terminal members 10 are provided with binding screws 25 that extend into the openings 11 for the purpose of securing the conductors therein. 1

The terminal block, as illustrated, is adaptable for either two or three wire connections and is provided with the auxiliary terminal members 17 and 18 for the purpose of permitting the series and shunt windings (not shown) of the electrical measuring instrument to be disconnected from each other for testing purposes. When it is desired to test the instrument, by impressing a relatively low voltage on the shunt winding, the screw 23 is removed. to thus disconnect the shunt and the series winding from each other.

While we have shown our device in its preferred form, it will be understood that various modifications may be made therein without departing from the spirit and scope of the invention, as set forth in .theappended claims.

We claim as our invention: 7

1. A terminal block comprising an in sulatin member having a recess in one side thereof and openings extending substantially at right angles from the recess to the outer and inner surfaces of the block, a terminal member disposed in the recess and having openings in the opposite side thereof that register with the openings in the insulating member, a second terminal member disposed on the surface of the insulating member adjacent to the inwardly extending opening, and a connecting member disposed in the inwardly extending opening for securing the terminal members in posi- 4 tion'.

2. A terminal block comprising an insulating member having a recess in one side thereof and alined openings extending from the recess to the outer and inner surfaces of the block, a terminal member having two openings therein disposed in the recess, the openings registering with the openings in the insulating member, a second terminal member disposed on the surface of the insulating member adjacent to the inwardly extending opening, and means extending thereof and openings extending from the sides of the recess to the inner and outer surfaces of the block, a terminal member disposed in the recess and having openings therein that register with the openings in the insulating member, a second terminal member disposed on the inner surface of the insulating member, and a bolt extending through one of the openings for securing the terminal members in position. v

4:. A terminal block comprising an insulating member having a recess in one side thereof and openings extending at substantially right angles to the recess to the inner and outer surfaces of the block, a terminal member disposed in the recess, a second terminal member disposed on the I inner surface of the insulating member, and

means extending through the said terminal members and one of the openings for securing the terminal members in position.

5. A terminal block comprising an insulating member having a recess in one side thereof and a plurality of openings extending from said recess, terminal members disposed within the recess and at the ends of the said openings to constitute pairs having openings therein that register with the openings in the insulating member, and means for operatively connecting the respective pairs of terminal members together.

6. A terminal block comprising an in sulating member having a recess in one side thereof and outwardly and inwardly extending openings from the recess, a terminal member disposed in the recess and having openings therein that register with the openings in the insulating member, a second terminal member disposed on the surface of the insulating member adjacent to one of the openings, and means extending through the terminal members and one of the open ings for securing the terminal members in position and for electrically connecting the same together.

7. A terminal block comprising an insulating member having a recess in one side thereof and inwardly and outwardly extending openings from the recess, a terminal member disposed in the recess, a terminal member disposed on the surface of the insulating member adjacent to one of the openings, said terminal member having openings therein that register with the openings in the insulating member, and a connecting member disposed inthe inwardly extending opening for securing the terminal members in position.

member disposed in the recess, a terminal member disposed on the surface of the msulating member and adjacent to one of the openings, said terminal members -.having openings therein that register with the openings in' thefinsulatinf: member, anda 2' connecting member for a ustably securing the terminal members in position and for electrically connecting the same together.

In testimony whereof we have hereunto subscribed our names this 24th day of J an., I"

WILLIAM M. BRADSHAW. WALTER G. MYLIUS. 

